24.83Your practical first-ballad formula

If you're handed a simple melody tomorrow, do this:

1. Find key.
2. Find basic chords.
3. Convert triads to 7ths.
4. Add 9ths where melody permits.
5. Keep LH sparse.
6. Put melody clearly on top.
7. Use smooth inversions.
8. Add one secondary dominant.
9. Add borrowed iv near an important cadence.
10. Make a 2–4 bar intro.
11. Add tiny fills only in gaps.
12. End with a deliberate cadence.

That is enough for a convincing first arrangement.